We have proposed to use the information from the Chlamydia Genome Project database to clone and characterize new chlamydial genes and to test their potential as a subunit vaccine. The first part of the proposed project has been completed and has resulted in the identification of six antigens that were selected based on their demonstrated immunogenicity in animals surviving chlamydial infection. This immunogenicity indicates their potential for generating a protective immune response when used as a subunit vaccine. We now seek funding to proceed to the second stage of this project. We now plan to test these six antigen sequences, alone and in combination, for their potential to generate both humoral and cell based immunity in mice. "Naked" plasmid DNAs, encoding these antigens, will be used to vaccinate animals. Intramuscular and intranasal administration of DNA will be tested and compared based on the ability to generate humoral and/or cell-based immunity. Antigens found to be immunogenic will then be tested for protective immunity by a chlamydial challenge. Chlamydia trachomatis infection of animals have been established in- house and both intranasal and intravaginal challenges of vaccinated animals will be tested. PROPOSED COMMERCIAL APPLICATIONS: No effective vaccine for the prevention of chlamydial infections currently exists. There are an estimated 3 million new infections annually in the U.S., resulting in over $3 billion in associated health care costs. These figures do not include world-wide trachoma infections. Outside the U.S., chlamydial infections are the leading cause of preventable blindness. The proposed research in this application is the first step in the development of an effective DNA vaccine against chlamydia. Such a vaccine would have immediate, widespread commercial demand, on an international scale.